1. Field of the Invention
The present invention relates to an image forming apparatus for forming a plurality of page images formed on one side of a sheet on both sides of a sheet.
2. Related Background Art
A conventional image forming apparatus has a 2-in-1 mode and a 4-in-1 mode and records images on the front and back sides of a recording sheet. The 2-in-1 mode copies two originals on the same side of one sheet, and the 4-in-1 mode copies four originals on the same side of one sheet.
The layouts of images formed after originals are stacked in a stacker of an image forming apparatus are shown in FIGS. 21 and 22 which illustrate the directions of originals and sheet feed directions.
FIG. 23 illustrates the definitions of an original direction and a sheet feed direction. The original direction indicates whether an original placed in a stacker at a correct direction as viewed by a user positioned in front of the image forming apparatus, is vertically long or horizontally long relative to the arrow direction shown in FIG. 23. The sheet feed direction indicates whether a long edge or short edge of a sheet is first fed.
FIG. 21 shows the positional relationship between images recorded on the both sides of a sheet in the 2-in-1 mode, and FIG. 22 shows the positional relationship between images recorded on the both sides of a sheet in the 4-in-1 mode. In FIGS. 21 and 22, the sheet in the "front" column shows the state when viewed down to a paper ejection tray 2. A bold line 3 shows a staple fastened with a stapler 4. Originals are stacked in the order of 1, 2, 3, 4, 5, 6, 7, and 8 from the top to the bottom. If the numerals 1 to 8 are in the correct direction as viewed from a user, it is assumed that each original is placed at the correct direction.
However, both the sheets of originals copied in the 2-in-1 mode and the sheets of originals copied in the 4-in-1 mode are fastened by a single staple 3. Therefore, these sheets can be turned over either on the vertical side or on the horizontal side. Assuming that the contents of a sheet on the front side are at the correct direction, the user cannot know at once which side is used to turn over pages. The user is required to check the correct turnover direction through a try and error basis.
In order to avoid this problem, the user adds another staple, resulting in a cumbersome work with possible errors.
If the contents of an original are written vertically, the copied images are disposed from the left to the right as the originals in the original stacker 1 are copied sequentially downward. Therefore, a user feels something different from the original images.